The Monongah mining disaster of Monongah, West Virginia, occurred on December 6, 1907, and has been described as "the worst mining disaster in American History". The explosion occurred in Fairmont Coal Company’s No. 6 and No. 8 mines.

The disaster

Rescuers going into the mouth of the No. 6 mine, newspaper photo.

On Friday, December 6, 1907, there were officially 367 men in the two mines, although the actual number was much higher as officially registered workers often took their children and other relatives into the mine to help. At 10:28 AM an explosion occurred that killed most of the men inside the mine instantly. The blast caused considerable damage to both the mine and the surface. The ventilation systems, necessary to keep fresh air supplied to the mine, were destroyed along with many railcars and other equipment. Inside the mine the timbers supporting the roof were blown down which caused further issues as the roof collapsed. An official cause of the explosion was not determined, but investigators at the time believed that an electrical spark or one of the miners' open flame lamps ignited coal dust or methane gas.[1]